The rehabilitation of patients with severely resorbed mandibular ridges can be a clinical challenge when rehabilitation with endosteal implants is not the elected treatment. Historically, weighted mandibular complete dentures have been used successfully to manage patients with severely resorbed ridges, and the weight of their cast metal has been calculated by using the weight of the wax and the density of the alloy. This clinical report presents the management of an 87-year-old woman with a severely resorbed mandibular ridge by using a weighted mandibular complete denture fabricated by using selective laser melting (SLM) technology in which the weight of the metal base was calculated by using the volume of the digital file used for manufacture.Reasons for failures of bilayer yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) restorations include the core-veneer interface bond strength. The influence of the veneering method on the bond strength of veneered Y-TZP is unclear.
The purpose of this systematic review and meta-analysis was to evaluate the effect of the veneering method on the bond strength of bilayer Y-TZP.
This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Searches were performed on PubMed/MEDLINE, Web of Science (Core Collection), and Scopus for invitro studies evaluating the effect of the veneering technique on the bond strength of bilayer Y-TZP. Statistical analyses were performed with random-effect models (α=.05).
From 619 identified studies, 140 were selected for full-text analysis and 16 were included. Manual searching yielded no additional articles. The meta-analyses comprised 15 studies, and 1 study was included only in the descriptive analysis. Meta-analyfor the veneering of Y-TZP. In contrast, the cemented method may be unsuitable for veneering Y-TZP structures because of its lower bond strength than the hand-layered veneering technique.
Core-veneer interfacial adhesion was equivalent for pressed and hand-layered veneering techniques. Improved bond strength, regardless of the veneer ceramic material type, was achieved by the fused veneering method, which seems to be a promising choice for the veneering of Y-TZP. In contrast, the cemented method may be unsuitable for veneering Y-TZP structures because of its lower bond strength than the hand-layered veneering technique.Prosthetic complications have been frequently reported in implant-supported complete-arch prosthesis. Prosthetic restorations designed with an all-on-four treatment concept and fabricated from zirconia ceramic may be used to overcome these problems.
The purpose of this biomechanical study was to evaluate the effects of cantilever length and inclination of implant on the stress distribution in bone tissue, implant, and a monolithic zirconia ceramic-lithium disilicate glass-ceramic superstructure for all-on-four prosthesis.
All-on-four mandibular prosthesis fabricated from a zirconia and lithium disilicate glass-ceramic (LDGC) superstructure was designed with cantilever lengths of either 5 mm or 9 mm and posterior implants with a distal tilt of either 15 or 30 degrees. Stresses were evaluated with a simulated application of a static load of 600 N.
Increasing implant inclination from 15 to 30 degrees led to a decrease in maximum principal stress (MaxPS) values of approximately 4 to 7 MPa in cortical bonerst and second grooves of the same implant. An increase in implant inclination led to in an increase in vMS values in the core structure.
In zirconia ceramic restorations by using an all-on-four design with an LDGC superstructure, short cantilevers may be preferable because they result in a more favorable distribution of stress than long cantilevers. An increase in implant angulation from 15 to 30 degrees decreased MaxPS values in cortical bone.
In zirconia ceramic restorations by using an all-on-four design with an LDGC superstructure, short cantilevers may be preferable because they result in a more favorable distribution of stress than long cantilevers. An increase in implant angulation from 15 to 30 degrees decreased MaxPS values in cortical bone.Direct-metal laser-sintering (DMLS) technologies are being used to manufacture removable partial dentureframeworks; however, the build parameters are not well documented.
The purpose of this invitro study was to investigate the impact of 3 different build angulations on a dental cobalt-chromium(Sint-Tech ST2724G) alloy by comparing the tensile properties and nanoindentation hardness. The null hypothesis was that no change would be found in the tensile properties of the different build angulation groups.
Dumbbell-shaped tensile specimens were produced by using stereolithographic models in accordance with American Society for Testing and Materials testing standard E8/E8M-16ae1. Specimens (n=10) were fabricated by using DMLS additive manufacturing with 3 different angulations (0, 45, and 90 degrees). Tensile testing was carried out to assess yield strength (0.2% permanent offset), elongation (%) at failure, and ultimate tensile strength (GPa). Scanning electron microscope (SEM) images were used to analyze relation to the laser melt pattern does impact the mechanical properties of the alloy.
The cobalt-chromium dental alloy manufactured by DMLS produced favorable mechanical properties. The SEM analysis combined with the tensile test results suggest that the direction of the build angle in relation to the laser melt pattern does impact the mechanical properties of the alloy.A high metal-ceramic bond strength is important for successful dental restorations. However, studies on the evaluation of the bond strength of porous metal-ceramic restorations compared with conventional ones are scarce.
The purpose of this invitro study was to compare the bond strength of a porous metal-ceramic structure with conventional metal-ceramic restorations.
Ten porous specimens were fabricated by selective laser sintering (SLS) according to the International Organization for Standardization 9693-12012, 10 specimens without porosity by SLS, and 10 cobalt-chromium (Co-Cr) cast specimens without porosity. https://www.selleckchem.com/products/rhapontigenin.html The ceramic was applied with the pressing method. A 3-point bend test was performed with a universal testing machine, and the data were statistically analyzed by using 1-way analysis of variance (α=.05).
The mean ±standard deviation bond strength of the porous group fabricated by SLS was the lowest (35.6 ±9.1 MPa), that of the group without porosity in the casting method was 43.5 ±7.8 MPa, and that of the group without porosity fabricated by SLS was the highest (47.